IMO Shortlist 2013 problem C2
Kvaliteta:
Avg: 0,0Težina:
Avg: 6,0 In the plane,
red points and
blue points are marked so that no three of the marked points are collinear. One needs to draw
lines not passing through the marked points and dividing the plane into several regions. The goal is to do it in such a way that no region contains points of both colors.
Find the minimal value of
such that the goal is attainable for every possible configuration of
points.



Find the minimal value of


Izvor: Australia